Electrical powered vehicle and power feeding device for vehicle

ABSTRACT

An electrical powered vehicle includes a secondary self-resonant coil, a secondary coil, a rectifier, and a power storage device. The secondary self-resonant coil is configured to be magnetically coupled with a primary self-resonant coil of a power feeding device by magnetic field resonance, and allow reception of high frequency power from the primary self-resonant coil. The secondary coil is configured to allow reception of electric power from the secondary self-resonant coil by electromagnetic induction. The rectifier rectifies the electric power received by the secondary coil. The power storage device stores the electric power rectified by the rectifier.

This is a Continuation of application Ser. No. 12/929,445 filed Jan. 25,2011, which is a continuation of Ser. No. 12/681,332 filed Apr. 1, 2010,which claims the benefit of Application No. 2007-277973 filed in Japanon Oct. 25, 2007. The disclosure of the prior application is herebyincorporated by reference herein in its entirety.

TECHNICAL FIELD

The present invention relates to an electrical powered vehicle and apower feeding device for a vehicle. Particularly, the present inventionrelates to the technique of charging a power storage device mounted onan electrical powered vehicle wirelessly from a power source external tothe vehicle.

BACKGROUND ART

Great attention is focused on electrical powered vehicles such as anelectric vehicle and hybrid vehicle as environment-friendly vehicles.These vehicles incorporate an electric motor for generating a drivingforce for running, and a rechargeable power storage device for storingelectric power to be supplied to the electric motor. A hybrid vehiclerefers to a vehicle incorporating an internal combustion engine as apower source, in addition to an electric motor, or a vehicle furtherincorporating a fuel cell in addition to a power storage device as thedirect current power source for driving the vehicle. A hybrid vehicleincorporating an internal combustion engine and an electric motor as thepower source is already put into practice.

Among the hybrid vehicles there is known a vehicle that allows chargingof the vehicle-mounted power storage device from a power source externalto the vehicle, likewise with an electric vehicle. The so-called“plug-in hybrid vehicle” that allows the power storage device to becharged from a general household power supply by connecting the plugsocket located at an establishment with the charging inlet provided atthe vehicle is known.

As a method for power transfer, attention is recently focused onwireless electrical power transmission not using power supply cordsand/or cables for electrical transmission. Three promising approaches ofthis wireless power transfer technique are known, i.e. power transferusing electromagnetic induction, power transfer using radio waves, andpower transfer through the resonance method.

The resonance method thereof is directed to power transfer takingadvantage of the resonance of the electromagnetic field, allowingelectric power as high as several kW to be transferred over a relativelylong distance (for example, several meters) (refer to Non-PatentDocument 1).

-   Patent Document 1: Japanese Patent Laying-Open No. 2001-8380-   Patent Document 2: Japanese Patent Laying-Open No. 8-126106-   Non-Patent Document 1: Andre Kurs et al., “Wireless Power Transfer    via Strongly Coupled Magnetic Resonances” [online], Jul. 6, 2007,    Science, vol. 317, pp. 83-86, [retrieved on Sep. 12, 2007], Internet    <URL: http://www.sciencemag.org/cgi/reprint/317/5834/83.pdf>

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention

The aforementioned “Wireless Power Transfer via Strongly CoupledMagnetic Resonances” is silent about specific measures in the case wherethe wireless power transfer approach by the resonance method is appliedto the charging of a vehicle-mounted power storage device from a powersource external to the vehicle.

Therefore, an object of the present invention is to provide anelectrical powered vehicle receiving charging power wirelessly from apower source external to the vehicle by the resonance method, andallowing charging of a vehicle-mounted power storage device.

Another object of the present invention is to provide a power feedingdevice for a vehicle for wireless power transfer of charging power to anelectrical powered vehicle by the resonance method.

Means for Solving the Problems

An electrical powered vehicle of the present invention includes asecondary self-resonant coil, a secondary coil, a rectifier, a powerstorage device, and an electric motor. The secondary self-resonant coilis configured to be magnetically coupled with a primary self-resonantcoil located outside the vehicle by magnetic field resonance, allowingreception of electric power from the primary self-resonant coil. Thesecondary coil is configured to allow reception of electric power fromthe secondary self-resonant coil by electromagnetic induction. Therectifier rectifies the electric power received at the secondary coil.The power storage device stores the electric power rectified by therectifier. The electric motor receives supply of electric power from thepower storage device to generate a driving force for the vehicle.

Preferably, the number of windings of the secondary self-resonant coilis set based on the voltage of the power storage device, the distancebetween the primary self-resonant coil and secondary self-resonant coil,and the resonant frequency of the primary and secondary self-resonantcoils.

Preferably, the electrical powered vehicle further includes reflectivemeans. The reflective means is formed at the rear side of the secondaryself-resonant coil and secondary coil with respect to the powerreceiving direction from the primary self-resonant coil, and reflectsthe magnetic flux output from the primary self-resonant coil towards thesecondary self-resonant coil.

Preferably, the electrical powered vehicle further includes anadjustment device. The adjustment device is configured to allowadjustment of the resonant frequency of the secondary self-resonant coilby modifying at least one of the capacitance and inductance of thesecondary self-resonant coil.

More preferably, the electrical powered vehicle further includes anelectric power detection device, and a control device. The electricpower detection device detects the electric power received by thesecondary self-resonant coil and the secondary coil. The control devicecontrols the adjustment device such that the electric power detected bythe electric power detection device is at a maximum.

Preferably, the electrical powered vehicle further includes an electricpower detection device, and a communication device. The electric powerdetection device detects electric power received by the secondaryself-resonant coil and the secondary coil. The communication device isconfigured to allow transmission of the detection value of electricpower detected by the electric power detection device to a power feedingdevice external to the vehicle, including a primary self-resonant coil.

The secondary self-resonant coil is preferably arranged at a lowerportion of the vehicle body.

Furthermore, the secondary self-resonant coil is preferably disposedwithin a hollow tire of the wheel.

Preferably, a plurality of sets of the secondary self-resonant coil andsecondary coil are provided. The plurality of secondary coils areconnected to the rectifier, parallel with each other.

Preferably, the electrical powered vehicle further includes a voltageconverter. The voltage converter is disposed between the secondary coiland the power storage device to carry out a boosting operation or adown-converting operation based on the voltage of the power storagedevice.

Preferably, the electrical powered vehicle further includes first andsecond relays. The first relay is arranged between the power storagedevice and the electric motor. The second relay is arranged between thepower storage device and the secondary coil. When the first relay isturned ON and the electric motor is driven by the electric power of thepower storage device, the second relay is also turned ON together withthe first relay.

According to the present invention, a power feeding device for a vehicleincludes a high frequency power driver, a primary coil, and a primaryself-resonant coil. The high frequency power driver is configured toallow conversion of the electric power received from a power source intohigh frequency power that can achieve magnetic field resonance fortransmission to the vehicle. The primary coil receives high frequencypower from the high frequency power driver. The primary self-resonantcoil is configured to be magnetically coupled with the secondaryself-resonant coil mounted on the vehicle by magnetic field resonance,and allow transfer of the high frequency power received from the primarycoil by electromagnetic induction to the secondary self-resonant coil.

Preferably, the power feeding device for a vehicle further includesreflective means. The reflective means is formed at the rear side of theprimary self-resonant coil and primary coil with respect to the powertransferring direction from the primary self-resonant coil forreflecting the magnetic flux output from the primary self-resonant coilin the power transferring direction.

Preferably, the power feeding device for a vehicle further includes acommunication device and a control device. The communication device isconfigured to allow reception of a detection value of reception powertransmitted from the vehicle receiving supply of power from the powerfeeding device for a vehicle. The control device adjusts the frequencyof the high frequency power by controlling the high frequency powerdriver such that the reception power is at a maximum based on thedetection value of the reception power received by the communicationdevice.

Preferably, the power feeding device for a vehicle further includes acommunication device and a control device. The communication device isconfigured to allow reception of information transmitted from thevehicle to which power from the power feeding device for a vehicle issupplied. The control device controls the high frequency power driversuch that high frequency power is generated according to the number ofvehicles receiving supply of electric power from the power feedingdevice for a vehicle based on the information received by thecommunication device.

Further preferably, the control device stops the high frequency powerdriver upon determination that there is no vehicle receiving supply ofelectric power from the power feeding device for a vehicle.

Preferably, the power feeding device for a vehicle further includes anadjustment device. The adjustment device is configured to allowadjustment of the resonant frequency of the primary self-resonant coilby modifying at least one of the capacitance and inductance of theprimary self-resonant coil.

Further preferably, the power feeding device for a vehicle furtherincludes a communication device and a control device. The communicationdevice is configured to allow reception of a detection value ofreception power transmitted from the vehicle to which power from thepower feeding device for a vehicle is supplied. The control devicecontrols the adjustment device such that the reception power is at amaximum based on the detection value of the reception power received bythe communication device.

Preferably, the power feeding device for a vehicle further includes acommunication device and a selection device. The communication device isconfigured to allow reception of a detection value of the receptionpower received from the vehicle to which power from the power feedingdevice for a vehicle is supplied. A plurality of sets of the primaryself-resonant coil and primary coil are provided. The selection deviceselects from the plurality of primary coils a primary coil receivinghigh frequency power from the high frequency power driver and connectsthe selected primary coil with the high frequency power driver such thatthe reception power is at a maximum based on the detection value of thereception power received by the communication device.

Preferably, a plurality of sets of the primary self-resonant coil andprimary coil are provided. The plurality of primary coils are connectedparallel with each other with respect to the high frequency powerdriver.

Effects of the Invention

In the present invention, the electric power from a power source isconverted into high frequency power by the high frequency power driverof the power feeding device for a vehicle, and applied to the primaryself-resonant coil by the primary coil. Accordingly, the primaryself-resonant coil and the secondary self-resonant coil of theelectrical powered vehicle are magnetically coupled by the magneticfield resonance, and electric power is transferred from the primaryself-resonant coil to the secondary self-resonant coil. Then, theelectric power received by the secondary self-resonant coil is rectifiedby the rectifier to be stored in the power storage device of theelectrical powered vehicle.

According to the present invention, charging power is transferredwirelessly to an electrical powered vehicle from a power source externalto the vehicle, allowing charging of a power storage device mounted onthe vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 represents an entire configuration of a charging system to whichis applied an electrical powered vehicle according to a first embodimentof the present invention.

FIG. 2 is a diagram to describe the mechanism of power transfer by theresonance method.

FIG. 3 is a functional block diagram representing an entireconfiguration of a powertrain of the electrical powered vehicle of FIG.1.

FIG. 4 represents an exemplified arrangement of a reflective wall.

FIG. 5 is a functional block diagram representing an entireconfiguration of a powertrain of an electrical powered vehicle accordingto a second embodiment.

FIG. 6 represents an exemplified configuration of the secondaryself-resonant coil of FIG. 5.

FIG. 7 represents an exemplified configuration of a secondaryself-resonant coil according to a first modification of the secondembodiment.

FIG. 8 represents an exemplified configuration of a secondaryself-resonant coil according to a second modification of the secondembodiment.

FIG. 9 is a vertical cross sectional view of the wheel and itsneighborhood of an electrical powered vehicle according to a thirdembodiment.

FIG. 10 represents a configuration around a power receiving region of anelectrical powered vehicle according to a fourth embodiment.

FIG. 11 represents a configuration around a power receiving region of anelectrical powered vehicle according to a first modification of thefourth embodiment.

FIG. 12 represents a configuration around a power receiving region of anelectrical powered vehicle according to a second modification of thefourth embodiment.

FIG. 13 represents an entire configuration of a charging system to whichis applied an electrical powered vehicle according to a fifthembodiment.

FIG. 14 is a functional block diagram representing an entireconfiguration of a powertrain of the electrical powered vehicle of FIG.13.

FIG. 15 is a functional block diagram representing a configuration of apower feeding device of FIG. 13.

FIG. 16 represents the relationship between the frequency of the highfrequency power and charging power.

FIG. 17 represents an entire configuration of a charging systemaccording to a sixth embodiment.

FIG. 18 is a functional block diagram representing a configuration ofthe power feeding device of FIG. 17.

FIG. 19 is functional block diagram representing a configuration of apower feeding device according to a seventh embodiment.

FIG. 20 represents a configuration of a power feeding device accordingto an eighth embodiment.

FIG. 21 represents a configuration of a power feeding device accordingto a ninth embodiment.

FIG. 22 represents a configuration of a power feeding device accordingto a tenth embodiment.

FIG. 23 represents a configuration of a power feeding device accordingto an eleventh embodiment.

DESCRIPTION OF THE REFERENCE CHARACTERS

100, 100A, 100B, 100B-1, 100B-2 electrical powered vehicle, 110, 110A to110C, 110-1, 110-2, 110-3, 340 secondary self-resonant coil, 112variable capacitor, 114 variable capacitive diode, 116-1, 116-2self-resonant coil, 118 switch, 120, 120-1, 120-2, 120-3, 350 secondarycoil, 130 rectifier, 140 power storage device, 150 PCU, 152 boostconverter, 154, 156 inverter, 160 motor, 162, 164 motor generator, 170engine, 172 power split device, 174 driving wheel, 180, 180A, 180Bvehicle ECU, 182 voltage sensor, 184 current sensor, 190, 250communication device, 200, 200A to 200G power feeding device, 210 ACpower source, 220, 220A, 220B, 220-1, 220-2, 220-3 high frequency powerdriver, 230, 230-1, 230-2, 230-3, 320 primary coil, 240, 240A to 240C,240-1, 240-2, 240-3, 330 primary self-resonant coil; 260, 260A, 260BECU, 270 selection device, 310 high frequency power source, 360 load,410, 420 reflective wall, 510 hollow tire, 520 vehicle body, SMRI, SMR2system main relay, C1, C2 smoothing capacitor, PL1, PL2 positive line,NL negative line.

BEST MODES FOR CARRYING OUT THE INVENTION

Embodiments of the present invention will be described hereinafter indetail with reference to the drawings. The same or correspondingelements in the drawings have the same reference characters allotted,and description thereof will not be repeated.

First Embodiment

FIG. 1 represents an entire configuration of a charging system to whichis applied an electrical powered vehicle according to a first embodimentof the present invention. Referring to FIG. 1, the charging systemincludes an electrical powered vehicle 100, and a power feeding device200.

Electrical powered vehicle 100 includes a secondary self-resonant coil110, a secondary coil 120, a rectifier 130, and a power storage device140. Electrical powered vehicle 100 further includes a power controlunit (hereinafter, also referred to as “PCU”) 150, and a motor 160.

Secondary self-resonant coil 110 is arranged at a lower portion of thevehicle body. This secondary self-resonant coil 110 is an LC resonantcoil having both ends open (non-connected). Secondary self-resonant coil110 is configured to be magnetically coupled with primary self-resonantcoil 240 (described afterwards) of power feeding device 200 by themagnetic field resonance to allow reception of the electric power fromprimary self-resonant coil 240. Specifically, secondary self-resonantcoil 110 has its number of windings set appropriately such that the Qvalue representing the intensity of resonance between primaryself-resonant coil 240 and secondary self-resonant coil 110, the κ valuerepresenting the degree of coupling thereof and the like become higherbased on the voltage of power storage device 140, the distance betweenprimary self-resonant coil 240 and secondary self-resonant coil 110, theresonant frequency of primary self-resonant coil 240 and secondaryself-resonant coil 110, and the like.

Secondary coil 120 is configured to allow reception of electric powerfrom secondary self-resonant coil 110 by electromagnetic induction, andis preferably aligned coaxial with secondary self-resonant coil 110.Secondary coil 120 outputs the electric power received from secondaryself-resonant coil 110 towards rectifier 130. Rectifier 130 rectifies ACpower of high frequency received from secondary coil 120 for output topower storage device 140. Alternative to rectifier 130, an AC/DCconverter converting the AC power of high frequency from secondary coil120 into the voltage level of power storage device 140 may be employed.

Power storage device 140 is a DC power source that can be charged andrecharged, formed of a secondary battery such as lithium ion or nickelhydride. The voltage of power storage device 140 is approximately 200V,for example. Power storage device 140 stores the electric power suppliedfrom rectifier 130, as well as electric power generated by motor 160, aswill be described afterwards. Power storage device 140 supplies thestored electric power to PCU 150.

A capacitor of large capacitance may be employed as power storage device140. Any power buffer is applicable as long as it can temporarily storeelectric power from rectifier 130 and/or motor 160 and supply the storedelectric power to PCU 150.

PCU 150 converts the electric power supplied from power storage device140 into AC voltage for output to motor 160 to drive motor 160. Further,PCU 150 rectifies the electric power generated by motor 160 for outputto power storage device 140, which is charged.

Motor 160 receives the electric power supplied from power storage device140 via PCU 150 to generate the vehicle driving force, which is providedto the wheel. Motor 160 receives kinetic energy from the wheel or enginenot shown to generate electric power. The generated electric power isprovided to PCU 150.

Power feeding device 200 includes an AC power source 210, a highfrequency power driver 220, a primary coil 230, and a primaryself-resonant coil 240.

AC power source 210 is a power source external to the vehicle; forexample, a system power source. High frequency power driver 220 convertsthe electric power received from AC power source 210 into high frequencypower that can achieve magnetic field resonance for transmission fromprimary self-resonant coil 240 to secondary self-resonant coil 110 ofthe vehicle side, and supplies the converted high frequency power toprimary coil 230.

Primary coil 230 is configured to allow power transfer to primaryself-resonant coil 240 by electromagnetic induction, and is preferablyaligned coaxial with primary self-resonant coil 240. Primary coil 230outputs the electric power received from high frequency power driver 220to primary self-resonant coil 240.

Primary self-resonant coil 240 is arranged in the proximity of theground. This primary self-resonant coil 240 is an LC resonant coilhaving both ends open, and is configured to be magnetically coupled withsecondary self-resonant coil 110 of electrical powered vehicle 100 bymagnetic field resonance, and allow power transfer to secondaryself-resonant coil 110. Specifically, primary self-resonant coil 240 hasits windings set appropriately such that the Q value, the degree ofcoupling κ and the like become higher based on the voltage of powerstorage device 140 charged by the electric power supplied from primaryself-resonant coil 240, the distance between primary self-resonant coil240 and secondary self-resonant coil 110, the resonant frequency betweenprimary self-resonant coil 240 and secondary self-resonant coil 110, andthe like.

FIG. 2 is a diagram to describe the mechanism of power transfer by theresonance method. Referring to FIG. 2, this resonance method is similarto the resonance of two tuning forks. By the resonance of two LCresonant coils having the same natural frequency via the magnetic field,electric power is transferred wirelessly from one coil to the othercoil.

In response to a flow of high frequency power towards primary coil 320by high frequency power source 310, a magnetic field is built up atprimary coil 320 to generate high frequency power at primaryself-resonant coil 330 by electromagnetic induction. Primaryself-resonant coil 330 functions as an LC resonator based on the coil'sinductance and the floating capacitance between the conductor lines.Primary self-resonant coil 330 is magnetically coupled by magnetic fieldresonance with secondary self-resonant coil 340 similarly functioning asan LC resonator, and having a resonant frequency identical to that ofprimary self-resonant coil 330 to transfer electric power towardssecondary self-resonant coil 340.

The magnetic field built up at secondary self-resonant coil 340 by theelectric power received from primary self-resonant coil 330 causesgeneration of high frequency power by electromagnetic induction atsecondary coil 350, which is supplied to load 360.

The corresponding relationship with the elements in FIG. 1 will bedescribed hereinafter. AC power source 210 and high frequency powerdriver 220 of FIG. 1 correspond to high frequency power source 310 ofFIG. 2. Primary coil 230 and primary self-resonant coil 240 of FIG. 1correspond to primary coil 320 and primary self-resonant coil 330,respectively, of FIG. 2. Secondary self-resonant coil 110 and secondarycoil 120 of FIG. 1 correspond to secondary self-resonant coil 340 andsecondary coil 350, respectively, of FIG. 2. Rectifier 130 and powerstorage device 140 of FIG. 1 correspond to load 360 of FIG. 2.

FIG. 3 is a functional block diagram representing an entireconfiguration of a powertrain of electrical powered vehicle 100 ofFIG. 1. Referring to FIG. 3, electrical powered vehicle 100 includes apower storage device 140, a system main relay SMR1, a boost converter152, inverters 154 and 156, smoothing capacitors C1, C2, motorgenerators 162 and 164, an engine 170, a power split device 172, adriving wheel 174, and a vehicle ECU (Electronic Control Unit) 180.Electrical powered vehicle 100 also includes secondary self-resonantcoil 110, secondary coil 120, rectifier 130, and system main relay SMR2.

This electrical powered vehicle 100 is a hybrid vehicle incorporating anengine 170 and motor generator 164 as the driving source. Engine 170 andmotor generators 162 and 164 are coupled with power split device 172.Electrical powered vehicle 100 runs by the driving force generated by atleast one of engine 170 and motor generator 164. The motive powergenerated by engine 170 is divided into two paths by power split device172. One path is directed to driving wheel 174 and the other path isdirected to motor generator 162.

Motor generator 162 is an AC rotating electric machine formed of, forexample, a 3-phase AC synchronous electric motor having a permanentmagnet embedded in a rotor. Motor generator 162 generates electric powerusing the kinetic energy of engine 170 that is divided by power splitdevice 172. For example, when the state of charge (hereinafter, alsoreferred to as SOC) of power storage device 140 becomes lower than apredetermined value, engine 170 is started to cause power generation bymotor generator 162 for charging power storage device 140.

Motor generator 164 also is an AC rotating electric machine formed of,for example, a 3-phase AC synchronous electric motor having a permanentmagnet embedded in a rotor, similar to motor generator 162. Motorgenerator 164 generates a driving force using at least one of theelectric power stored in power storage device 140 and the electric powergenerated by motor generator 162. The driving force of motor generator164 is transmitted to driving wheel 174.

In a braking mode of the vehicle or in an acceleration reducing mode ata downward slope, the mechanical energy stored at the vehicle as akinetic energy or position energy is used for the rotational drive ofmotor generator 164 through driving wheel 174, whereby motor generator164 operates as a power generator. Accordingly, motor generator 164operates as a regenerative brake converting the running energy intoelectric power to generate the braking force. The electric powergenerated by motor generator 164 is stored in power storage device 140.

Motor generators 162 and 164 correspond to motor 160 shown in FIG. 1.Power split device 172 is formed of a planetary gear set including a sungear, a pinion gear, a carrier, and a ring gear. The pinion gear engageswith the sun gear and ring gear. The carrier supports the pinion gear toallow rotation on its axis, and is coupled to the crankshaft of engine170. The sun gear is coupled to the rotational shaft of motor generator162. The ring gear is coupled to the rotational shaft of motor generator164 and to driving wheel 174.

System main relay SMR1 is disposed between power storage device 140 andboost converter 152. System main relay SMR1 electrically connects powerstorage device 140 with boost converter 152 when a signal SE1 fromvehicle ECU 180 is rendered active, and disconnects the path betweenpower storage device 140 and boost converter 152 when signal SE1 isrendered inactive.

Boost converter 152 responds to a signal PWC from vehicle ECU 180 toboost the voltage output from power storage device 140 for output ontopositive line PL2. For example, a DC chopper circuit constitutes thisboost converter 152.

Inverters 154 and 156 are provided corresponding to motor generators 162and 164, respectively. Inverter 154 drives motor generator 162 based ona signal PWI1 from vehicle ECU 180. Inverter 156 drives motor generator164 based on a signal PWI2 from vehicle ECU 180. A 3-phase bridgecircuit, for example, constitutes inverters 154 and 156.

Boost converter 152 and inverters 154 and 156 correspond to PCU 150 ofFIG. 1. Secondary self-resonant coil 110, secondary coil 120, andrectifier 130 are as described with reference to FIG. 1. System mainrelay SMR2 is disposed between rectifier 130 and power storage device140. System main relay SMR2 electrically connects power storage device140 with rectifier 130 when a signal SE2 from vehicle

ECU 180 is rendered active, and disconnects the path between powerstorage device 140 and rectifier 130 when signal SE2 is renderedinactive.

Vehicle ECU 180 generates signals PWC, PWI1 and PWI2 to drive boostconverter 152, motor generator 162, and motor generator 164,respectively, based on the accelerator pedal position, vehicle speed,and signals from various sensors. The generated signals PWC, PWI1 andPWI2 are output to boost converter 152, inverter 154, and inverter 156,respectively.

In a vehicle running mode, vehicle ECU 180 renders signal SE1 active toturn on system main relay SMR1, and renders signal SE2 inactive to turnoff system main relay SMR2.

In a charging mode of power storage device 140 from AC power source 210external to the vehicle (FIG. 1) by means of secondary self-resonantcoil 110, secondary coil 120 and rectifier 130, vehicle ECU 180 renderssignal SE1 inactive to turn off system main relay SMR1, and renderssignal SE2 active to turn on system main relay SMR2.

In electrical powered vehicle 100, system main relays SMR1 and SMR2 areturned off and on, respectively, in a charging mode of power storagedevice 140 from external AC power source 210 (FIG. 1). The chargingpower of high frequency received by secondary self-resonant coil 110magnetically coupled with primary self-resonant coil 240 (FIG. 1) ofpower feeding device 200 by magnetic field resonance is transferred tosecondary coil 120 by electromagnetic induction, rectified by rectifier130, and then supplied to power storage device 140.

In order to improve the efficiency of power transfer by magnetic fieldresonance, at least one of power feeding device 200 and electricalpowered vehicle 100 may have a reflective wall provided to reflect themagnetic flux.

FIG. 4 represents an exemplified arrangement of such a reflective wall.FIG. 4 is an enlarged view around secondary self-resonant coil 110 andsecondary coil 120 of electrical powered vehicle 100, and primary coil230 and primary self-resonant coil 240 of power feeding device 200.

Referring to FIG. 4, electrical powered vehicle 100 has a reflectivewall 410 of low magnetic permeability provided at the rear side ofsecondary self-resonant coil 110 and secondary coil 120 with respect tothe electric power receiving direction from primary self-resonant coil240, so as to surround secondary self-resonant coil 110 and secondarycoil 120, allowing the magnetic flux output from primary self-resonantcoil 240 to be reflected towards secondary self-resonant coil 110.

Power feeding device 200 has a reflective wall 420 of low magneticpermeability provided at the rear side of primary self-resonant coil 240and primary coil 230 with respect to the power transferring directionfrom primary self-resonant coil 240 so as to surround primaryself-resonant coil 240 and primary coil 230, allowing the magnetic fluxoutput from primary self-resonant coil 240 to be reflected towards thepower transferring direction.

Reflective wall 410 of the vehicle side also serves to block magneticleakage into the compartment and towards the vehicle-mounted electricalequipment.

In the first embodiment, the electric power from AC power source 210 isconverted into high frequency power by high frequency power driver 220of power feeding device 200, and applied to primary self-resonant coil240 by primary coil 230. Accordingly, primary self-resonant coil 240 ismagnetically coupled with secondary self-resonant coil 110 of electricalpowered vehicle 100 by magnetic field resonance, whereby electric poweris transferred from primary self-resonant coil 240 to secondaryself-resonant coil 110. The electric power received by secondaryself-resonant coil 110 is rectified by rectifier 130 to be supplied topower storage device 140 of electrical powered vehicle 100. According tothe present first embodiment, the charging power from AC power source210 external to the vehicle is transferred wirelessly to electricalpowered vehicle 100 to allow charging of power storage device 140mounted thereon.

By providing reflective walls 410 and 420 formed of members of lowmagnetic permeability, the efficiency of power transfer by magneticfield resonance can be improved in the first embodiment. Moreover,magnetic leakage into the compartment and towards the vehicle-mountedequipment can be blocked by reflective wall 410.

Second Embodiment

It is to be noted that the distance between the power feeding device andvehicle may vary depending upon the state of the vehicle (loading state,air pressure of tire, and the like). The change in the distance betweenthe primary self-resonant coil of the power feeding device and thesecondary self-resonant coil of the vehicle causes a change in theresonant frequency of the primary self-resonant coil and secondaryself-resonant coil. In this context, the second embodiment has theresonant frequency of the secondary self-resonant coil on part of thevehicle variable.

FIG. 5 is a functional block diagram representing an entireconfiguration of a powertrain of an electrical powered vehicle 100A ofthe second embodiment. Referring to FIG. 5, electrical powered vehicle100A is based on the configuration of electrical powered vehicle 100shown in FIG. 3, additionally including a voltage sensor 182 and acurrent sensor 184, and also including a secondary self-resonant coil110A and vehicle ECU 180A instead of secondary self-resonant coil 110and vehicle ECU 180, respectively.

Secondary self-resonant coil 110A is configured to allow the capacitanceof the coil to be modified based on a control signal from vehicle ECU180A. Secondary self-resonant coil 110A can change the LC resonantfrequency by modifying the capacitance.

FIG. 6 represents an exemplified configuration of secondaryself-resonant coil 110A of FIG. 5. Referring to FIG. 6, secondaryself-resonant coil 110A includes a variable capacitor connected betweenconductor lines. Variable capacitor 112 has a variable capacitance basedon a control signal from vehicle ECU 180A (FIG. 5). By altering thecapacitance thereof, the capacitance of secondary self-resonant coil110A is rendered variable. As compared to the case where a variablecapacitor 112 is not provided so that the capacitance of the secondaryself-resonant coil will be determined by the floating capacitancebetween the conductor lines, the capacitance of secondary self-resonantcoil 110A can be modified by altering the capacitance of variablecapacitor 112 connected between the conductor lines. Therefore, the LCresonant frequency of secondary self-resonant coil 110A can be modifiedby altering the capacitance of variable capacitor 112.

Referring to FIG. 5 again, voltage sensor 182 detects a voltage Vs ofpower storage device 140 to provide the detection value to vehicle ECU180A. Current sensor 184 detects a current Is flowing from rectifier 130to power storage device 140 to output the detection value to vehicle ECU180A. In a charging mode of power storage device 140 from power feedingdevice 200

(FIG. 1) external to the vehicle, vehicle ECU 180A calculates thecharging power of power storage device 140 based on each detection valuefrom voltage sensor 182 and current sensor 184. Vehicle ECU 180A adjuststhe LC resonant frequency of secondary self-resonant coil 110A byadjusting the capacitance of variable capacitor 112 (FIG. 6) ofsecondary self-resonant coil 110A such that the charging power is at amaximum.

Thus, in the present second embodiment, the LC resonant frequency ofsecondary self-resonant coil 110A can be adjusted by variable capacitor112. The LC resonant frequency of secondary self-resonant coil 110A isadjusted by vehicle ECU 180A such that the charging power of powerstorage device 140 is at a maximum. According to the present secondembodiment, the efficiency of power transfer from power feeding device200 to electrical powered vehicle 100A can be maintained even if thestate of the vehicle (loading state, air pressure of tire, and the like)changes.

First Modification of Second Embodiment

A variable capacitive diode may be employed instead of variablecapacitor 112 in order to adjust the LC resonant frequency of thesecondary self-resonant coil.

FIG. 7 represents an example of a configuration of a secondaryself-resonant coil according to a first modification of the secondembodiment. Referring to FIG. 7, a secondary self-resonant coil 110Bincludes a variable capacitive diode 114 connected between conductorlines. Variable capacitive diode 114 has a capacitance that is variablebased on a control signal from vehicle ECU 180A (FIG. 5) to render thecapacitance of secondary self-resonant coil 110B variable by modifyingthe capacitance thereof, likewise with variable capacitor 112.

Vehicle ECU 180A adjusts the capacitance of variable capacitive diode114 of secondary self-resonant coil 110B to adjust the LC resonantfrequency of secondary self-resonant coil 110B such that the chargingpower supplied from power feeding device 200 external to the device(FIG. 1) towards power storage device 140 is at a maximum.

An advantage similar to that of the second embodiment described abovecan be achieved by the present first modification.

Second Modification of Second Embodiment

The second embodiment and first modification thereof were describedbased on a secondary self-resonant coil having a variable capacitance toallow adjustment of the resonant frequency of the secondaryself-resonant coil. Alternatively, the inductance of the secondaryself-resonant coil may be rendered variable.

FIG. 8 represents an example of a configuration of a secondaryself-resonant coil according to a second modification of the secondembodiment. Referring to FIG. 8, a secondary self-resonant coil 110Cincludes self-resonant coils 116-1 and 116-2, and a switch 118 connectedbetween self-resonant coils 116-1 and 116-2. Switch 118 is turned on/offbased on a control signal from vehicle ECU 180A (FIG. 5).

When switch 118 is turned on, self-resonant coils 116-1 and 116-2 arecoupled, so that the inductance of overall secondary self-resonant coil110C becomes greater. Therefore, the LC resonant frequency of secondaryself-resonant coil 110C can be modified by turning switch 118 on/off.

Vehicle ECU 180A turns switch 118 of secondary self-resonant coil 110Con or off to adjust the LC resonant frequency of secondary self-resonantcoil 110C based on the charging power supplied from power feeding device200 (FIG. 1) external to the vehicle to power storage device 140.

Although the above description is based on a secondary self-resonantcoil 110C including two self-resonant coils 116-1 and 116-2 and oneswitch 118, the LC resonant frequency of secondary self-resonant coil110C can be adjusted more finely by providing more self-resonant coilsand a corresponding switch for connection/disconnection thereof.

An advantage similar to that of the second embodiment set forth abovecan be achieved by the second modification.

Third Embodiment

Secondary self-resonant coil 110 has both ends open (non-connected), andthe influence of an obstacle on the magnetic field resonance is low. Inthis context, the secondary self-resonant coil is provided inside ahollow tire of the wheel in the third embodiment.

An entire configuration of the powertrain of an electrical poweredvehicle according to the third embodiment is similar to that ofelectrical powered vehicle 100 shown in FIG. 3.

FIG. 9 is a vertical sectional view of the wheel of the electricalpowered vehicle and the neighborhood thereof according to the thirdembodiment. Referring to FIG. 9, the wheel is formed of a hollow tire510. Inside hollow tire 510, a secondary self-resonant coil 110 coaxialwith the wheel is provided. Secondary self-resonant coil 110 is fixedlyattached to the wheel. In the proximity of the wheel in a vehicle body520, a secondary coil 120 is disposed, allowing power reception byelectromagnetic induction from secondary self-resonant coil 110 providedin hollow tire 510.

When the vehicle is brought to a halt such that the wheel havingsecondary self-resonant coil 110 incorporated in hollow tire 510 islocated above primary self-resonant coil 240 of the power feedingdevice, secondary self-resonant coil 110 in hollow tire 510 ismagnetically coupled with primary self-resonant coil 240 by the magneticfield resonance. Electric power is transferred from primaryself-resonant coil 240 towards secondary self-resonant coil 110 inhollow tire 510. The electric power received by secondary self-resonantcoil 110 is transferred by electromagnetic induction to secondary coil120 disposed in the proximity of the wheel, and then supplied to powerstorage device 140 not shown.

In the third embodiment, the axes of secondary self-resonant coil 110and primary self-resonant coil 240 do not match and are not parallelwith each other. However, the axes of secondary self-resonant coil 110and primary self-resonant coil 240 do not necessarily have to match orbe parallel in power transfer by magnetic filed resonance.

The third embodiment is advantageous in that the interior of a hollowtire can be utilized efficiently as the space for arrangement ofsecondary self-resonant coil 110.

Fourth Embodiment

In the fourth embodiment, a plurality of sets of the secondaryself-resonant coil and secondary coil are provided on part of thevehicle. Accordingly, the electric power transferred from the powerfeeding device can be received reliably and sufficiently even if thehalting position of the vehicle is deviated from a defined position.

FIG. 10 represents a configuration in the proximity of the powerreceiving region of the electrical powered vehicle in the fourthembodiment. FIG. 10 is based on an example in which there are, but notlimited to, three sets of secondary self-resonant coils and secondarycoils.

Referring to FIG. 10, the electrical powered vehicle includes secondaryself-resonant coils 110-1, 110-2, and 110-3, secondary coils 120-1,120-2, and 120-3, and a rectifier 130. Secondary self-resonant coils110-1, 110-2, and 110-3 are disposed parallel to the bottom face of thevehicle at the lower portion of the vehicle body. Secondary coils 120-1,120-2, and 120-3 are provided corresponding to secondary self-resonantcoils 110-1, 110-2, and 110-3, respectively, and connected parallel toeach other with respect to rectifier 130.

The remaining configuration of the electrical powered vehicle in thefourth embodiment is identical to that of the first or secondembodiment.

Since a plurality of sets of secondary self-resonant coils and secondarycoils are provided in the fourth embodiment, the electric powertransferred from the power feeding device can be received reliably andsufficiently even if the halting position of the vehicle is deviatedfrom a defined position.

According to the fourth embodiment, any leaking power not received atsecondary self-resonant coil 110-2 identified as the main powerreceiving coil can be received by another secondary self-resonant coilin the case where the vehicle is brought to a halt at a defined positionwith respect to secondary self-resonant coil 110-2. Therefore, the powertransfer efficiency can be improved.

First Modification of Fourth Embodiment

The above description is based on the case where a set of a secondaryself-resonant coil and secondary coil is provided in plurality. Leakageof the power transmission can be reduced by just providing a pluralityof secondary self-resonant coils.

FIG. 11 represents a configuration in the proximity of the powerreceiving region of the electrical powered vehicle according to a firstmodification of the fourth embodiment. FIG. 11 is based on an example inwhich there are, but not limited to, three secondary self-resonantcoils.

Referring to FIG. 11, the electrical powered vehicle includes secondaryself-resonant coils 110-1, 110-2, and 110-3, a secondary coil 120, and arectifier 130. Secondary self-resonant coils 110-1, 110-2, and 110-3 arearranged parallel to the bottom face of the vehicle at the lower portionof the body. Secondary coil 120 is provided corresponding to secondaryself-resonant coil 110-2, and is connected to rectifier 130.

The remaining configuration of the electrical powered vehicle accordingto the first modification of the fourth embodiment is similar to that ofthe first or second embodiment.

In the first modification of the fourth embodiment, the powertransmission efficiency can be improved since any leaking power notreceived at secondary self-resonant coil 110-2 can be received atanother secondary self-resonant coil.

Second Modification of Fourth Embodiment

Although only a plurality of secondary self-resonant coils are providedin the above-described first modification, leakage of the transferredpower can also be reduced by providing a plurality of secondary coilsinstead.

FIG. 12 represents a configuration in the proximity of the powerreceiving region of the electrical powered vehicle according to a secondmodification of the fourth embodiment. FIG. 12 is based on an example inwhich there are, but not limited to, three secondary coils.

Referring to FIG. 12, the electrical powered vehicle includes asecondary self-resonant coil 110, secondary coils 120-1, 120-2, and120-3, and a rectifier 130. Secondary coil 120-2 is providedcorresponding to secondary self-resonant coil 110. Secondary coils120-1, 120-2, and 120-3 are arranged parallel to the bottom face of thevehicle at the lower portion of the body, and parallel to each otherwith respect to rectifier 130.

The remaining configuration of the electrical powered vehicle accordingto the second modification of the fourth embodiment is similar to thatof the first or second embodiment.

In the second modification of the fourth embodiment, the powertransmission efficiency can be improved since any leaking power notreceived at secondary coil 120-2 can be received at another secondarycoil.

Fifth Embodiment

As mentioned above, variation in the distance between the primaryself-resonant coil of the power feeding device and the secondaryself-resonant coil of the vehicle will cause change in the resonantfrequency of the primary self-resonant coil and secondary self-resonantcoil. In the fifth embodiment, the power receiving state of theelectrical powered vehicle is transmitted to the power feeding device,and the frequency of the high frequency power, i.e. resonant frequency,is adjusted at the power feeding device such that the receiving electricpower of the electrical powered vehicle is at a maximum.

FIG. 13 represents an entire configuration of a charging system to whichthe electrical powered vehicle of the fifth embodiment is applied.Referring to FIG. 13, the charging system includes an electrical poweredvehicle 100B, and a power feeding device 200A.

Electrical powered vehicle 100B is based on the configuration ofelectrical powered vehicle 100 shown in FIG. 1, and additional includesa communication device 190. Communication device 190 is a communicationinterface for wireless communication with a communication device 250provided at power feeding device 200.

Power feeding device 200A is based on the configuration of power feedingdevice 200 shown in FIG. 1, and additionally includes a communicationdevice 250 and an ECU 260, as well as a high frequency power driver 220Ainstead of high frequency power driver 220. Communication device 250 isa communication interface for wireless communication with communicationdevice 190 provided at electrical powered vehicle 100B. ECU 260 controlshigh frequency power driver 220A based on the information fromelectrical powered vehicle 100B received by communication device 250.

FIG. 14 is a functional block diagram representing an entireconfiguration of a powertrain of electrical powered vehicle 100B shownin FIG. 13. Referring to FIG. 14, electrical powered vehicle 100B isbased on the configuration of electrical powered vehicle 100 shown inFIG. 3, and additionally includes a voltage sensor 182, a current sensor184, and communication device 190, as well as a vehicle ECU 180B insteadof vehicle ECU 180.

In a charging mode of power storage device 140 from power feeding device200A (FIG. 13) external to the vehicle, vehicle ECU 180B calculates acharging power PWR of power storage device 140 based on respectivedetection values from voltage sensor 182 and current sensor 184, andprovides the calculated charging power PWR to communication device 190.Communication device 190 transmits charging power PWR received fromvehicle ECU 180B by radio towards power feeding device 200A external tothe vehicle.

The remaining configuration of electrical powered vehicle 100B issimilar to that of electrical powered vehicle 100 shown in FIG. 3.

FIG. 15 is a functional block diagram representing a configuration ofpower feeding device 200A shown in FIG. 13. Referring to FIG. 15, in apower feeding mode from power feeding device 200A to electrical poweredvehicle 100B (FIG. 13), communication device 250 receives charging powerPWR of electrical powered vehicle 100B transmitted from communicationdevice 190 (FIG. 13) of electrical powered vehicle 100B, and providesthe received charging power PWR to ECU 260.

ECU 260 can set a frequency f1 of the high frequency power generated byhigh frequency power driver 220A, and provides the set frequency f1 tohigh frequency power driver 220A to adjust the frequency of the highfrequency power, i.e. resonant frequency. ECU 260 adjusts the frequencyof the high frequency power generated by high frequency power driver220A to the level of fs such that charging power PWR is at a maximum asshown in FIG. 16, based on charging power PWR of electrical poweredvehicle 100B received from communication device 250.

High frequency power driver 220A responds to a command from ECU 260 toconvert the power received from AC power source 210 into a highfrequency power at frequency fs, and provides the high frequency powerhaving the frequency of fs to primary coil 230.

In the fifth embodiment, the power receiving state of electrical poweredvehicle 100B is transmitted to power feeding device 200A bycommunication device 190, and received at communication device 250 ofpower feeding device 200A. The frequency of the high frequency powergenerated by high frequency power driver 220A is adjusted by ECU 260such that charging power PWR of the electrical powered vehicle is at amaximum. According to the fifth embodiment, power can be transferred athigh efficiency from power feeding device 200A to electrical poweredvehicle 100B even when the vehicle state (loading state, air pressure oftire, and the like) changes.

Sixth Embodiment

The sixth embodiment is based on a configuration in which the electricpower supplied from the power feeding device can be adjusted accordingto the number of electrical powered vehicles receiving power supply fromthe power feeding device.

FIG. 17 represents an entire configuration of a charging systemaccording to the sixth embodiment. FIG. 17 corresponds to the case wheretwo electrical powered vehicles receive electric power from the powerfeeding device. However, the number of electrical powered vehicle is notlimited thereto.

Referring to FIG. 17, the charging system includes electrical poweredvehicles 100B-1 and 100B-2, and a power feeding device 200B. Each ofelectrical powered vehicles 100B-1 and 100B-2 is based on aconfiguration similar to that of electrical powered vehicle 100B shownin FIG. 14, and is configured to allow communication with power feedingdevice 200B by communication device 190 (FIG. 14). Each of electricalpowered vehicles 100B-1 and 100B-2 transmits to power feeding device200B notification of requesting power feeding from power feeding device200B.

Upon receiving a power feed request from electrical powered vehicles100B-1 and 100B-2, power feeding device 200B supplies charging powersimultaneously to electrical powered vehicles 100B-1 and 100B-2.

FIG. 18 is a functional block diagram representing a configuration ofpower feeding device 200B of FIG. 17. Referring to FIG. 18, powerfeeding device 200B includes an AC power source 210, a high frequencypower driver 220B, a primary coil 230, a primary self-resonant coil 240,a communication device 250, and an ECU 260A.

Communication device 250 receives a power feeding request fromelectrical powered vehicles 100B-1 and 100B-2. ECU 260A identifies anelectrical powered vehicle that is to receive power supply from powerfeeding device 200B based on the information received by communicationdevice 250. ECU 260A outputs a power command PR to high frequency powerdriver 220B such that high frequency power is generated according to thenumber of electrical powered vehicles receiving power supply from powerfeeding device 200B.

When ECU 260A determines that there is no electrical powered vehiclereceiving power supply from power feeding device 200B based on theinformation received by communication device 250, a shut down commandSDWN to stop high frequency power driver 220B is generated and providedto high frequency power driver 220B.

High frequency power driver 220B responds to power command PR from ECU260A to generate high frequency power according to the number ofelectrical powered vehicles receiving power supply from power feedingdevice 200B, and provides the generated high frequency power to primarycoil 230.

High frequency power driver 220B stops its operation upon receiving ashut down command SDWN from ECU 260A.

According to the sixth embodiment, an electrical powered vehiclereceiving power supply from power feeding device 200B is identified bycommunication between the power feeding device and an electrical poweredvehicle, and high frequency power according to the number of electricalpowered vehicles receiving power supply is generated from high frequencypower driver 220B. Therefore, the power feeding capability will not bedegraded even if there are a plurality of electrical powered vehiclereceiving feeding power.

Since high frequency power driver 220B is stopped when determination ismade that there is no electrical powered vehicle receiving power supplyfrom power feeding device 200B based on the information received atcommunication device 250, unnecessary output of power from the powerfeeding device can be prevented.

Seventh Embodiment

The resonant frequency of the secondary self-resonant coil at thevehicle side is made variable in the second embodiment, whereas thefrequency of the high frequency power generated by the high frequencypower driver of the power feeding device is made variable in the fifthembodiment. In the seventh embodiment, the resonant frequency of theprimary self-resonant coil at the power feeding device side is madevariable.

FIG. 19 is a functional block diagram representing a configuration of apower feeding device according to the seventh embodiment. Referring toFIG. 19, power feeding device 200C includes an AC power source 210, ahigh frequency power driver 220, a primary coil 230, a primaryself-resonant coil 240A, a communication device 250, and an ECU 260B.

Primary self-resonant coil 240A is configured to allow modification ofits capacitance based on a control signal from ECU 260B. Primaryself-resonant coil 240A allows the LC resonant frequency to be modifiedby altering the capacitance. The configuration of this primaryself-resonant coil 240A is similar to that of secondary self-resonantcoil 110A shown in FIG. 6.

In a power feeding mode from power feeding device 200C to electricalpowered vehicle 100B (FIG. 14), communication device 250 receivescharging power PWR of electrical powered vehicle 100B transmitted fromcommunication device 190 (FIG. 14) of electrical powered vehicle 100B,and outputs the received charging power PWR to ECU 260B.

ECU 260B adjusts the LC resonant frequency of primary self-resonant coil240A by adjusting the capacitance of variable capacitor 112 (FIG. 6) ofprimary self-resonant coil 240A such that charging power PWR ofelectrical powered vehicle 100B is at a maximum.

Likewise with the first and second modifications of the secondembodiment, a primary self-resonant coil 240B having a configurationsimilar to that of secondary self-resonant coil 110B shown in FIG. 7, ora primary self-resonant coil 240C having a configuration similar to thatof secondary self-resonant coil 110C shown in FIG. 8 may be employed,instead of primary self-resonant coil 240A.

According to the seventh embodiment, the LC resonant frequency ofprimary self-resonant coil 240A (240B, 240C) may be adjusted. The LCresonant frequency of primary self-resonant coil 240A (240B, 240C) isadjusted by ECU 260B such that the charging power of the electricalpowered vehicle receiving power supply from power feeding device 200C isat a maximum. Therefore, according to the seventh embodiment, theefficiency of power transfer from power feeding device 200C to anelectrical powered vehicle can be maintained even if the state of thevehicle (loading state, air pressure of tire, and the like) changes.

Eighth Embodiment

In the eighth embodiment, a plurality of sets of primary self-resonantcoils and primary coils are provided on the power feeding device side.

FIG. 20 represents a configuration of a power feeding device accordingto the eighth embodiment. FIG. 20 is based on an example in which thereare, but not limited to, three sets of primary self-resonant coils andprimary coils.

Referring to FIG. 20, power feeding device 200D includes an AC powersource 210, a high frequency power driver 220, primary coils 230-1,230-2, and 230-3, and primary self-resonant coils primary coils 240-1,240-2, and 240-3.

Primary self-resonant coils primary coils 240-1, 240-2, and 240-3 aredisposed parallel to the ground. Primary coils 230-1, 230-2, and 230-3are provided corresponding to primary self-resonant coils 240-1, 240-2,and 240-3, respectively, and connected parallel to each other withrespect to high frequency power driver 220.

In the eighth embodiment, the current from high frequency power driver220 flows in a concentrated manner to a primary coil corresponding tothe primary self-resonant coil having the lowest magnetic resistancewith the secondary self-resonant coil of the electrical powered vehiclereceiving power supply from power feeding device 200D. Therefore,electric power can be supplied from the power supply device to theelectrical powered vehicle reliably and sufficiently even if the haltingposition of the vehicle is deviated from a defined position.

Ninth Embodiment

Likewise with the eighth embodiment, the ninth embodiment has aplurality of sets of primary self-resonant coils and primary coilsprovided at the power feeding device. In contrast to the eighthembodiment having a primary self-resonant coil and primary coil selectedpassively, the ninth embodiment has a primary self-resonant coil andprimary coil selected positively such that the charging power is at amaximum at the electrical powered vehicle receiving power supply fromthe power feeding device.

FIG. 21 represents a configuration of a power feeding device accordingto the ninth embodiment. Referring to FIG. 21, a power feeding device200E is based on the configuration of power feeding device 200D of theeighth embodiment shown in FIG. 20, and additionally includes acommunication device 250 and a selection device 270.

In a power feeding mode from power feeding device 200E to electricalpowered vehicle 100B (FIG. 14), communication device 250 receivescharging power PWR of electrical powered vehicle 100B transmitted fromcommunication device 190 (FIG. 14) of electrical powered vehicle 100B.

Selection device 270 is connected between primary coils 230-1, 230-2,and 230-3 and high frequency power driver 220 to select and electricallyconnect with high frequency power driver 220 any one of primary coils230-1, 230-2, and 230-3. Selection device 270 selects a set of theprimary self-resonant coil and primary coil that provides the maximumcharging power PWR based on charging power PWR of electrical poweredvehicle 100B received from communication device 250, and connects theselected primary coil with high frequency power driver 220.

In the ninth embodiment, power can be transmitted reliably andsufficiently from the power feeding device to the electrical poweredvehicle even if the halting position of the vehicle is deviated from thedefined position, likewise with the eighth embodiment.

Tenth Embodiment

The eighth embodiment set forth above is based on the case where a setof a primary self-resonant coil and primary coil is provided inplurality. Only the primary self-resonant coil may be provided inplurality.

FIG. 22 represents a configuration of the power feeding device accordingto the tenth embodiment. FIG. 22 is based on an example in which thereare, but not limited to, three primary self-resonant coils.

Referring to FIG. 22, a power feeding device 200F includes an AC powersource 210, a high frequency power driver 220, a primary coil 230, andprimary self-resonant coils 240-1, 240-2, and 240-3.

Primary self-resonant coils 230-1, 230-2, and 230-3 are disposedparallel to the ground. Primary coil 230 is provided corresponding toprimary self-resonant coil 240-2, and connected to high frequency powerdriver 220.

Since the leakage of electric power not transmitted by primaryself-resonant coil 240-2 can be transferred to another primaryself-resonant coil in the tenth embodiment, the transmission efficiencycan be improved.

Eleventh Embodiment

In the eleventh embodiment, only the primary coils are provided inplurality.

FIG. 23 represents a configuration of a power feeding device of theeleventh embodiment. FIG. 23 is based on an example in which there are,but not limited to, three sets of primary coils and high frequency powerdrivers.

Referring to FIG. 23, a power feeding device 200G includes an AC powersource 210, high frequency power drivers 220-1, 220-2, and 220-3,primary coils 230-1, 230-2, and 230-3, and a primary self-resonant coil240.

Primary coils 230-1, 230-2, and 230-3 are arranged coaxial with primaryself-resonant coil 240, and connected to high frequency power drivers220-1, 220-2, and 220-3, respectively. High frequency power drivers220-1, 220-2, and 220-3 are connected parallel to AC power source 210,and output the high frequency power to primary coils 230-1, 230-2, and230-3, respectively.

In the eleventh embodiment, high power is provided to primaryself-resonant coil 240 by a plurality of high frequency power drivers220-1, 220-2, and 220-3, and primary coils 230-1, 230-2, and 230-3.Therefore, high power can be transferred from power feeding device 200Gto an electrical powered vehicle in the eleventh embodiment.

In each of the embodiments set forth above, a converter for boosting ordown-converting voltage based on the voltage of power storage device 140may be provided between rectifier 130 and power storage device 140.Alternatively, a transformer for voltage conversion based on the voltageof power storage device 140 may be provided between secondary coil 120and rectifier 130. Alternatively, an AC/DC converter for alternatingcurrent/direct current conversion based on the voltage of power storagedevice 140 may be provided instead of rectifier 130.

In a vehicle running mode in each of the embodiments set forth above,system main relay SMR1 is turned on and system main relay SMR2 is turnedoff by rendering signal SE1 active and rendering signal SE2 inactive,respectively. In a charging mode of power storage device 140 from ACpower source 210 external to the vehicle, system main relay SMR1 isturned off by rendering signal SE1 inactive and system main relay SMR2is turned on by rendering signal SE2 active. However, signals SE1 andSE2 may be rendered active at the same time to simultaneously turn onsystem main relays SMR1 and SMR2. Accordingly, it is possible to chargepower storage device 140 from an AC power source 210 external to thevehicle even during driving.

Each of the embodiments set forth above is based on a series/paralleltype hybrid vehicle having the power of engine 170 split by power splitdevice 172 for transmission to driving wheel 174 and motor generator162. The present invention is also applicable to other types of hybridvehicles. For example, the present invention is also applicable to theso-called series type hybrid vehicle using engine 170 only to drivemotor generator 162 and generating the driving force of the vehicle bymeans of motor generator 164 alone, to a hybrid vehicle having only theregenerative energy among the kinetic energy generated by engine 170 tobe collected as electric energy, as well as to a motor assist typehybrid vehicle with the engine as the main driving source and assistedby a motor, as necessary.

Further, the present invention is also applicable to a hybrid vehicleabsent of a boost converter 152.

Moreover, the present invention is applicable to an electric car thatruns only with an electric power, absent of an engine 170, and also to afuel cell vehicle further including a fuel cell in addition to a powerstorage device as the DC power source.

In the above description, motor generator 164 corresponds to an exampleof “electric motor” of the present invention. Reflective walls 410 and420 correspond to an example of “reflective means” of the presentinvention. Variable capacitor 112, variable capacitive diode 114, andswitch 118 correspond to an example of “adjustment device” of thepresent invention. Voltage sensor 182, current sensor 184, and vehicleECU 180A correspond to an example of “electric power detection device”of the present invention.

Further, vehicle ECU 180A corresponds to an example of “control devicefor controlling an adjustment device” of the present invention. Systemmain relays SMR1 and SMR2 correspond to an example of “first relay” and“second relay”, respectively, of the present invention. ECU 260Acorrespond to an example of “control device for controlling a highfrequency power driver” of the present invention. ECU 260B correspondsto an example of “a control device for controlling an adjustment device”of the present invention.

The embodiments disclosed herein may be implemented based on anappropriate combination thereof. It should be understood that each ofthe embodiments disclosed herein are illustrative and non-restrictive inevery respect. The scope of the present invention is defined by theappended claims, rather than the description set forth above, and allchanges that fall within limits and bounds of the claims, or equivalencethereof are intended to be embraced by the claims.

The invention claimed is:
 1. A power feeding device for an electricalpowered vehicle, comprising: a high frequency power driver configured toconvert electric power received from a power source into high frequencypower, a transmitting coil configured to be magnetically coupled with areceiving coil mounted on said vehicle by a magnetic field, and totransmit said high frequency power received from said high frequencypower driver, and a reflective wall formed at a rear side of saidtransmitting coil with respect to a power transferring direction fromsaid transmitting coil, to allow reflection of a magnetic flux outputfrom said transmitting coil in said power transferring direction, thetransmitting coil and the reflective wall being arranged spaced apartfrom each other.
 2. The power feeding device for an electrical poweredvehicle according to claim 1, wherein said transmitting coil is disposedin proximity to the ground, and at least a portion of said reflectivewall is disposed at a side deeper in the ground than said transmittingcoil.
 3. The power feeding device for an electrical powered vehicleaccording to claim 1, further comprising: a communication deviceconfigured to allow reception of a detection value of reception powertransmitted from a vehicle receiving power supply from the power feedingdevice for a vehicle, and a control device for adjusting a frequency ofsaid high frequency power by controlling said high frequency powerdriver such that said reception power is at a maximum based on thedetection value of said reception power received by said communicationdevice.
 4. The power feeding device for an electrical powered vehicleaccording to claim 1, further comprising: a communication deviceconfigured to allow reception of information transmitted from a vehiclereceiving power supply from the power feeding device for a vehicle, anda control device for controlling said high frequency power driver suchthat said high frequency power is generated according to the number ofvehicles receiving power supply from the power feeding device for avehicle, based on said information received by said communicationdevice.
 5. The power feeding device for an electrical powered vehicleaccording to claim 4, wherein said control device stops said highfrequency power driver when determination is made that there is novehicle receiving power supply from the power feeding device for avehicle.
 6. The power feeding device for an electrical powered vehicleaccording to claim 1, further comprising an adjustment device configuredto allow adjustment of a resonant frequency of said transmitting coil bymodifying at least one of a capacitance and inductance of saidtransmitting coil.
 7. The power feeding device for an electrical poweredvehicle according to claim 6, further comprising: a communication deviceconfigured to allow reception of a detection value of reception powertransmitted from a vehicle receiving power supply from the power feedingdevice for a vehicle, and a control device controlling said adjustmentdevice such that said reception power is at a maximum based on thedetection value of said reception power received by said communicationdevice.
 8. The power feeding device for an electrical powered vehicleaccording to claim 1, further comprising: a primary coil for receivingthe high frequency power from said high frequency power driver andtransmitting the received high frequency power to said transmitting coilby electromagnetic induction, and a communication device configured toallow reception of a detection value of reception power transmitted froma vehicle receiving power supply from the power feeding device for avehicle, wherein a plurality of sets of said transmitting coil and saidprimary coil are provided, the power feeding device further comprising aselection device for selecting, among the plurality of primary coils, aprimary coil receiving said high frequency power from said highfrequency power driver, and connecting the selected primary coil withsaid high frequency power driver such that said reception power is at amaximum based on the detection value of said reception power received bysaid communication device.
 9. The power feeding device for an electricalpowered vehicle according to claim 1, further comprising: a primary coilfor receiving the high frequency power from said high frequency powerdriver and transmitting the received high frequency power to saidtransmitting coil by electromagnetic induction, wherein a plurality ofsets of said transmitting coil and said primary coil are provided, andthe plurality of primary coils are connected parallel with each otherwith respect to said high frequency power driver.
 10. A power feedingdevice for an electrical powered vehicle, comprising: a high frequencypower driver configured to convert electric power received from a powersource into high frequency power, a primary LC resonator configured tobe magnetically coupled with a secondary LC resonator mounted on saidvehicle by a magnetic field, and to transmit said high frequency powerreceived from said high frequency power driver, and reflective meansformed at a rear side of said primary LC resonator with respect to apower transferring direction from said primary LC resonator, to allowreflection of a magnetic flux output from said primary LC resonator insaid power transferring direction, the primary LC resonator and thereflective means being arranged spaced apart from each other.
 11. Thepower feeding device for an electrical powered vehicle according toclaim 10, wherein said primary LC resonator is disposed in proximity tothe ground, and at least a portion of said reflective means is disposedat a side deeper in the ground than said primary LC resonator.
 12. Thepower feeding device for an electrical powered vehicle according toclaim 10, further comprising: a communication device configured to allowreception of a detection value of reception power transmitted from avehicle receiving power supply from the power feeding device for avehicle, and a control device for adjusting a frequency of said highfrequency power by controlling said high frequency power driver suchthat said reception power is at a maximum based on the detection valueof said reception power received by said communication device.
 13. Thepower feeding device for an electrical powered vehicle according toclaim 10, further comprising: a communication device configured to allowreception of information transmitted from a vehicle receiving powersupply from the power feeding device for a vehicle, and a control devicefor controlling said high frequency power driver such that said highfrequency power is generated according to the number of vehiclesreceiving power supply from the power feeding device for a vehicle,based on said information received by said communication device.
 14. Thepower feeding device for an electrical powered vehicle according toclaim 13, wherein said control device stops said high frequency powerdriver when determination is made that there is no vehicle receivingpower supply from the power feeding device for a vehicle.
 15. The powerfeeding device for an electrical powered vehicle according to claim 10,further comprising an adjustment device configured to allow adjustmentof a resonant frequency of said primary LC resonator by modifying atleast one of a capacitance and inductance of said primary LC resonator.16. The power feeding device for an electrical powered vehicle accordingto claim 15, further comprising: a communication device configured toallow reception of a detection value of reception power transmitted froma vehicle receiving power supply from the power feeding device for avehicle, and a control device controlling said adjustment device suchthat said reception power is at a maximum based on the detection valueof said reception power received by said communication device.
 17. Thepower feeding device for an electrical powered vehicle according toclaim 10, further comprising: a primary coil for receiving the highfrequency power from said high frequency power driver and transmittingthe received high frequency power to said primary LC resonator byelectromagnetic induction, and a communication device configured toallow reception of a detection value of reception power transmitted froma vehicle receiving power supply from the power feeding device for avehicle, wherein a plurality of sets of said primary LC resonator andsaid primary coil are provided, the power feeding device furthercomprising a selection device for selecting, among the plurality ofprimary coils, a primary coil receiving said high frequency power fromsaid high frequency power driver, and connecting the selected primarycoil with said high frequency power driver such that said receptionpower is at a maximum based on the detection value of said receptionpower received by said communication device.
 18. The power feedingdevice for an electrical powered vehicle according to claim 10, furthercomprising: a primary coil for receiving the high frequency power fromsaid high frequency power driver and transmitting the received highfrequency power to said primary LC resonator by electromagneticinduction, wherein a plurality of sets of said primary LC resonator andsaid primary coil are provided, and the plurality of primary coils areconnected parallel with each other with respect to said high frequencypower driver.